Working together to protect New Zealand

Weed Information

Weed Information Sheet

Browse Weeds by Alphabet

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Arrow Bamboo

Botanical Name

Pseudosasa japonica

Family

Poaceae (grass) family

Also known as

Bamboo

Where is it originally from?

Japan, South Korea

What does it look like?

Medium-sized, clump-forming perennial bamboo to 5 m tall with round, dark green stems with a white band just below each ring (node) where branches attach to stem and extensive underground root systems. Each branch has 1-7 leaves (35-40 mm wide x 250-300 mm long) and leaf sheaths are hairless, often purplish above, and are longer than the distance between nodes. Flowering can be continuous for several years, flattened grass-like flower spikes (4-9 cm long) are purplish on the exposed side.

Are there any similar species?

There are several other bamboo species in New Zealand.

Why is it weedy?

Forms very dense stands that exclude all other plants and that spread outwards by rapid growth of the thick rhizomes.

How does it spread?

Spread is vegetative by growth of rhizome, viable seed is uncommon.

What damage does it do?

Rapidly crowds out other plants as it forms dense stands.

Which habitats is it likely to invade?

Scrub, forest margins, riverbanks, roadsides, in or around plantations, urban areas, waste places.

What can I do to get rid of it?

  1. Cut down near the ground: Mulch leaves and stems, dig out rhizomes and root mass and dispose of them at a refuse transfer station.
    2. Cut down near the ground: Mulch stems and leaves. Allow to resprout, and spray the new growth with Amitrole (333ml/L) or Gallant (150ml/10L) plus penetrant before the regrowth reaches 60 cm tall. Again, allow to resprout and spray the regowth. Usually 4-5 applications are required before it stops resprouting.

What can I do to stop it coming back?

Monitor the site for regrowth from roots and rhizomes. Repeat treatments will usually be required. Plant the site with local, native plants to produce shade, but wait 6 months from last herbicide application.